1. Field of the Invention
The present invention relates generally to a method and apparatus for placing a liquid phase in contact with a vapor or gaseous phase, and more particularly, for placing the liquid phase in contact with the vapor or gaseous phase within an elongated annular chamber, such as to cause a reaction, heat and/or matter transfer and the later separation of the phases.
2. Description of the Prior Art
There are numerous processes in which it is desirable to place a liquid phase in contact with steam or a gaseous phase. One well know example is distillation where a gaseous phase or steam is bubbled within a liquid phase. Typically, the bubbling occurs in columns divided by a plurality of bubbling plates, with toothed parts placed on the plates or holes formed through the plates to provide for appropriate introduction of the gas into the liquid, such that steam or other rising gases bubble through falling liquid phases. However, such conventional devices have several disadvantages. In particular, the calculation of column diameter for a given working capacity depends largely upon the speed of the steam going through the column, which results in inflexible design restrictions. In addition, because the increase of steam speed will cause unacceptable alterations, such as foaming, in the operation of the apparatus, the only practical way of increasing capacity of the device is to increase the column area. The spacing between the plates is also largely dependent upon the materials used in the process. Consequently, the height of such a conventional apparatus, which is usually formed of numerous plates, is significantly influenced by the materials used in the process. Furthermore, the substantial volume of liquid and gaseous phases used in such processes usually requires substantial start-up and stop times associated with such processes.
Another well known system is the packing column in which the phase contact is achieved by the phases moving in countercurrent through complicated paths, which are determined by the existence of numerous inaccessible portions that occupy the volume of the column. Various arrangements of the packing column models have been developed that offer the greatest possible area for phase contact. The primary advantage of this approach over the bubbling column is its simpler construction and the substantial inaccessibility of the parts. However, the constant operation of the packing column apparatus is more difficult to maintain and adjust in order to avoid the "flooding problem" within the device. Specifically, there is a delicate equilibrium associated with the packing column that is easily broken upon the unwanted accumulation of liquid. This generally results in more burdensome and complex start-up and stop operations for such an apparatus than those for the bubbling column. In addition, the design of large capacity packing column units is complicated.
In other situations a liquid phase may be sprayed through a gaseous phase, which process may be repeated in successive chambers. Such approaches, however, have been found to be disadvantageous due to the large volume and substantial power requirements.
Still another relatively common approach for contacting a gas with a liquid is to introduce the liquid phase and the gaseous phase in countercurrent within a hollow cylindrical or conical member. Typically the liquid phase rotates downwardly along the sidewall of the member, with the gaseous phase rotating upwardly. In general, there are substantial difficulties associated with increasing the capacity of such systems.